In 1571 a special congregation was erected, the Sacred Congregation of the Index, which had the specific task to investigate those writings that were denounced in Rome as being not exempt of errors, to update the list of Pope Pius IV regularly and also to make lists of corrections in case a writing was not in itself damnable but only in need of correction and put on the list with a mitigating clause (e.g., donec corrigatur (forbidden if not corrected) or donec expurgetur (forbidden if not purged)). This sometimes resulted in very long lists of corrections, published in the Index Expurgatorius. Prohibitions made by other congregations (mostly the Holy Office) were simply passed on to the Congregation of the Index, where the final decrees were drafted and made public, after approval of the Pope (who always had the possibility to condemn an author personally—only a few examples, such as Lamennais and Hermes). The Congregation of the Index was abolished in 1917, when the rules on the reading of books were again reelaborated in the new Codex Iuris Canonici. From that date on the Holy Office (again) took care of the index.